More than one million U.S. inhabitants are diagnosed with cancer each year. Advanced imaging procedures are needed to more accurately define and non-invasively characterize neoplastic lesions. Image-guided therapies, including image-guided treatment planning for external beam conformal radiation therapy (stereotactic or intensity modulated) and for sealed and unsealed source radiation therapy, are clearly needed to optimally treat each individual patient. In addition, there continues to be a dramatic increase in the use of image-guided direct interventional procedures (interventional radiology or surgery) to improve both the prognostic outcome and the patient's quality of life following the intervention. In order to improve the pharmacological treatment of neoplastic processes, advanced physiological imaging techniques, using molecular imaging nuclear medicine approaches or magnetic resonance imaging, are being used to assess the efficacy of novel cytotoxic and/or cytostatic agents much earlier than current lesion size change criteria, such as RECIST, allow. Finally, a need has developed for such physiological imaging techniques to order to establish optimal biologic dose, rather than maximum tolerated dose, in clinical trials of cytostatic agents, e.g., antiangiogenic/antivascular drugs. For all of these reasons, a clear need exists for the training and development of independent scientists with expertise in image-guided therapy. In addition, clinical medical physicists with the necessary training in image-guided radiation therapy are sorely needed, as there is already a well-documented shortage of such individuals. To address the overwhelming need for such well trained individuals, only 11 graduate programs in medical physics are presently accredited by the Commission on Accreditation of Graduate Programs in Medical Physics (CAMPEP), and only 8 of those programs are in the U.S. These programs support the training and development of pre-doctoral medical physics trainees, and may also have associated post-doctoral education programs for training individuals for research careers in medical physics or related fields. However, any growth in training opportunities is being rapidly outpaced by the urgent need for individuals with solid interdisciplinary clinical and research training in image guided therapies. The primary goal of the proposed new training program is the development of independent research scientists and clinical medical physicists with the necessary training in advanced physiological imaging techniques and image-guided therapy. The availability of training grant funds would allow our CAMPEP-accredited Medical Physics Graduate Education Program, commonly ranked as one of the top programs in North America, to expand the number of trainees available to the field and to provide a unique environment for the training of medical physicists and imaging specialists with the interdisciplinary experience that is sorely needed in the current, and particularly in the future environment.